1. Technical Field
The present disclosure relates to a cylinder head of an internal combustion engine and an internal combustion engine installed in an automobile or the like. Particularly, the present disclosure relates to improvement of a configuration of supplying a secondary air to exhaust ports in a cylinder head.
2. Description of Related Art
Japanese Patent Application Publication No. 2009-250054 discloses a configuration of supplying a secondary air to exhaust ports in a cylinder head. The secondary air denotes a secondary air used for the purpose of exhaust purification by combustion of an unburnt gas and rapid temperature increase of a catalyst. JP 2009-250054 A discloses that a downstream part of a supply pipe of the secondary air is branched into plural branch pipes, and the secondary air is individually supplied through these branch pipes to each exhaust port in the cylinder head.
JP 2014-129748 A discloses a cylinder head with which exhaust manifolds are integrated thereinside. Specifically, the cylinder head is configured by integrating therewith port assemblies formed by assembling downstream parts in the exhaust flow direction of respective plural exhaust ports that communicate with corresponding cylinders of a multiple cylinder engine. The port assemblies are open at the cylinder head outer wall surface.